1. Field of the Invention
The present invention relates to a hydraulic torque transmitting device. More particularly, the present invention relates to a hydraulic torque transmitting device that has a damper mechanism provided on the outside of the main body thereof.
2. Background Information
A torque converter is a device that has three types of bladed wheels (i.e., impeller, turbine, and stator) on the inside thereof and transmits power by means of a fluid contained therein. A lockup device is provided within the fluid chamber of the torque converter to mechanically transmit torque to the output member. The lockup device comprises basically a piston that is movable in the axial direction and a damper mechanism that is provided between the piston and the output member. When torque fluctuations are transmitted from the engine to the lockup coupling, the fluctuations are absorbed and damped by the damper mechanism.
A structure in which the damper mechanism is provided externally to the fluid chamber of the torque converter is also known. Such an external damper mechanism is disposed between the tip of the crankshaft and the front cover of the torque converter and has the same structure as a conventional clutch disk assembly type damper mechanism. For example, the damper mechanism might comprise a first disk-shaped member, a pair of second disk-shaped members disposed axially on both sides of the first disk-shaped member, and an elastic member disposed inside a window hole of the first disk-shaped member and supported by the support part of the pair of second disk-shaped members. The inner circumferential border of such a damper mechanism might, for example, be fixedly coupled to the crankshaft with a bolt and the outer circumferential border might be fixedly coupled to the front cover of the torque converter with a bolt. In short, bolts or other fastening members must be used when the torque converter is assembled onto the crankshaft.
In view of the above. there exists a need for a hydraulic torque transmitting device, which overcomes the above mentioned problems in the prior art. This invention addresses this need in the prior art as well as other needs, which will become apparent to those skilled in the art from this disclosure.
One object of the present invention is to provide a hydraulic torque transmitting device that is configured to improve the ability to assemble the hydraulic torque transmitting device.
The foregoing objects can be attained by providing a hydraulic torque transmitting device for transmitting torque from the crankshaft of an engine to a transmission. The hydraulic torque transmitting device is equipped with a main body having a fluid chamber formed therein, a fluid driven member arranged within the fluid chamber of the main body and a damper mechanism for elastically coupling the main body directly to the crankshaft. The fluid driven member is arranged within the fluid chamber of the main body such that rotation of the main body causes fluid within the fluid chamber of the main body to rotate the fluid driven member. The fluid driven member has an output member adapted to be coupled to the transmission. The damper mechanism has a first and second coupling parts configured to elastically couple the main body to the crankshaft in a rotational direction. The first coupling part is coupled to the main body. The second coupling part is elastically coupled to the first coupling part and configured to be fixedly coupled directly to the crankshaft. Thus, the main body is coupled to the crankshaft such that the coupling is elastic in the rotational direction. The overall structure of this hydraulic torque transmitting device is simple because the main body is coupled directly to the crankshaft via the damper mechanism.
The hydraulic torque transmitting device can also be provided with an additional stipulation that the damper mechanism have an elastic member held by either one of the crankshaft and the main body and engaged with the other in such a manner that it is attachable and detachable in the axial direction. In other words, the damper mechanism includes at least one elastic member configured to be retained by one of the first and second coupling parts with the other of the first and second coupling parts being attachable and detachable in an axial direction. With this hydraulic torque transmission device, assembly can be accomplished by moving the main body in the axial direction so that it is close to the crankshaft. In short, the ability assemble of the hydraulic torque transmission device is improved because the device is separable in the axial direction at the damper mechanism.
In accordance with another aspect of the present invention, the hydraulic torque transmitting device can be further provided with the additional stipulation that the device main body have a plate forming the engine facing side wall of the fluid chamber. Also, the damper mechanism has the following: an elastic member support part formed on the plate; an elastic member, both rotational-direction borders and the axial direction transmission side of which are held by the elastic member support part; and a drive member that is fixedly coupled to the crankshaft and has an abutting part that is freely attachable and detachable in the axial direction with respect to both rotational-direction borders of the elastic member. With this hydraulic torque transmitting device, the elastic member is held by the plate of the main body in advance. Also, when the hydraulic torque transmitting device is assembled to the crankshaft, the abutting part of the drive member is made to engage from the axial direction with both circumferential-direction borders of the elastic member.
In accordance with another aspect of the present invention, the hydraulic torque transmitting device can further be provided with an additional stipulation that the plate have a holding part for holding the axial direction engine side of the elastic member. With this hydraulic torque transmitting device, the elastic member cannot drop from the plate because of the holding part.
In accordance with another aspect of the present invention, the hydraulic torque transmitting device can further be provided with an additional stipulation that a mass body be fixedly coupled to said crankshaft. With this hydraulic torque transmitting device, the structure is simple because the mass body is fixed directly to the crankshaft and does not engage with the hydraulic torque transmitting device or the damper mechanism.
In accordance with another aspect of the present invention, the hydraulic torque transmitting device can further be provided with an additional stipulation that the mass body have a disk-shaped member whose inner circumferential border is fixedly coupled to the crankshaft and a ring-shaped member fixedly coupled to the outer circumferential border of the disk-shaped member. With this hydraulic torque transmitting device, the axial dimension of the entire hydraulic torque transmitting device is shortened while still maintaining sufficient inertia because the ring-shaped member is fixedly coupled to the outer circumferential border of the disk-shaped member.